U.S. patent number 7,073,725 [Application Number 10/433,744] was granted by the patent office on 2006-07-11 for flow mixer.
This patent grant is currently assigned to Valquest Limited. Invention is credited to Jeremy Philip Swadling.
United States Patent |
7,073,725 |
Swadling |
July 11, 2006 |
Flow mixer
Abstract
A mixer tap for a shower has a body 1, with a cold water pipe
connection 2, a hot water pipe connection 3 and a mixed water
outlet connection 4. A flow control knob 5 and a water temperature
control knob 6 are provided at the front of the tap. The tap has a
flow mixer cartridge 11, which is sealed in a cavity 12 in the
body. The collar has three sealing grooves 15,16,17 carrying
O-rings 115,116,117. To one side, of the oblique groove 16, the
collar has a cold water port 22; whilst to the other side it has a
hot water port 23. These ports are in communication with the cold
and hot water connections 2,3 in the body. The connections are able
to be axially aligned with each other, since the ports 22,23 are
offset and isolated from each other by the oblique seal.
Inventors: |
Swadling; Jeremy Philip
(Rowlands Castle, GB) |
Assignee: |
Valquest Limited (Rowlands
Castle, GB)
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Family
ID: |
26245384 |
Appl.
No.: |
10/433,744 |
Filed: |
December 3, 2001 |
PCT
Filed: |
December 03, 2001 |
PCT No.: |
PCT/GB01/05342 |
371(c)(1),(2),(4) Date: |
June 06, 2003 |
PCT
Pub. No.: |
WO02/46853 |
PCT
Pub. Date: |
June 13, 2002 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20040046037 A1 |
Mar 11, 2004 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60264602 |
Jan 26, 2001 |
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Foreign Application Priority Data
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Dec 6, 2000 [GB] |
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0029714.3 |
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Current U.S.
Class: |
236/12.2 |
Current CPC
Class: |
G05D
23/1346 (20130101); G05D 23/1353 (20130101) |
Current International
Class: |
G05D
23/13 (20060101) |
Field of
Search: |
;236/12.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0566433 |
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Oct 1993 |
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EP |
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0694721 |
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Jan 1996 |
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EP |
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0068754 |
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Nov 2000 |
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WO |
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Primary Examiner: Tapolcai; William E.
Attorney, Agent or Firm: Ware, Fressola, Van Der Sluys &
Adolphson LLP
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is for entry into the U.S. national phase under
.sctn.371 for International Application No. PCT/GB01/05342 having
an international filing date of Dec. 3, 2001, and from which
priority is claimed under all applicable sections of Title 35 of
the United States Code including, but not limited to, Sections 120,
363 and 365(c), and which in turn claims the benefit to U.S.
Provisional Patent Application No. 60/264,602 filed on Jan. 26,
2001 and Great Britain Patent Application No. 0029714.3 filed on
Dec. 6, 2000.
Claims
The invention claimed is:
1. A cartridge for a flow mixer comprising: a barrel having: an
outlet at one end of said barrel, two aligned barrel portions and a
intermediate barrel portion and said barrel portions providing: two
respective liquid inlets spaced along said barrel, one to one side
of said intermediate barrel portion and said other to said other
side thereof, and a shuttle mounted in said barrel in sealing
relationship with said intermediate barrel portion and axially
movable in said barrel, said shuttle and said barrel being adapted
and arranged to: close one of said inlets by co-operation with said
inlet's respective barrel portion and said intermediate barrel
portion when moved towards this barrel portion; close said other
inlet by co-operation with its respective barrel portion and said
intermediate portion when moved in the other direction and allow
both inlets to be open in a mid position, and said shuttle being
apertured for flow therethrough, a thermostatic capsule arranged
within said barrel in the flow of liquid through said inlets and
adapted to control the position of said shuttle for selection of
flow from the two inlets, a combined-flow control member ("flow
controller") arranged downstream of said thermostatic capsule at
the outlet end of the barrel for controlling the combined flow from
the inlets and means including at least one finger passing through
said shuttle for longitudinal actuation of the flow controller to
control the combined flow.
2. A cartridge as claimed in claim 1, wherein said flow controller
is a sleeve mounted in said barrel and sealing in its closed
position against a closed end of said barrel, thereby closing an
outlet aperture in said wall of said barrel adjacent its end.
3. A cartridge as claimed in claim 2, wherein said flow control
sleeve seals against a seal captivated between said sleeve and the
end of said barrel.
4. A cartridge as claimed in claim 1, wherein said flow controller
is a movable obturator closing an open end of said barrel forming
the outlet.
5. A cartridge as claimed in claim 1, wherein said flow controller
is an apertured cylinder closing one or more outlet apertures in
said barrel at said outlet end with said end being closed.
6. A cartridge as claimed claim 1, wherein: said two aligned barrel
portions are distinct parts which are sealed together, with said
intermediate barrel portion being integrally connected to one of
said two barrel portions; and said shuttle is positioned and acts
between opposed ends of said two portions.
7. A cartridge as claimed in claim 1, wherein: the two aligned
portions and said intermediate portion of said barrel are all
integral parts of unitary construction, said inlets are apertures
in the aligned portions and said shuttle is contained completely
within said barrel.
8. A cartridge as claimed claim 1, wherein said actuating means for
said flow controller is an integral part of said flow
controller.
9. A cartridge as claimed in claim 7, wherein said actuating means
comprises one or more fingers integrally moulded with said flow
controller and engaging an actuator at the opposite side of said
shuttle from said flow controller and said thermostatic
capsule.
10. A cartridge as claimed in claim 7, wherein said actuating
fingers have clip formations clipped to said actuator.
11. A cartridge as claimed in claim 1, wherein said actuating means
comprises one or more fingers extending integrally extending from
said actuator and engaging said flow controller.
12. A cartridge as claimed in claim 1, wherein said actuating means
is separately formed and is engaged with both said flow controller
and said actuator.
13. A cartridge as claimed in claim 1, wherein said actuator
comprises a sleeve irrotationally held in said barrel and a rotary
member carried by said barrel, said sleeve and said rotary member
being adapted to convert rotation of said rotary member into
translation of said actuator and said flow controller.
14. A cartridge as claimed in claim 13, wherein said rotary member
is sealed to said barrel and said rotary member extends inside said
actuator.
15. A cartridge as claimed in claim 14, including means for
adjusting said thermostatic capsule comprising a second sleeve
irrotationally held in said actuator sleeve, a second rotary member
carried by said second sleeve and a capsule actuator irrotationally
held in said actuator sleeve and threadedly engaged with said
second rotary member.
16. A cartridge as claimed in claim 1, wherein said barrel, said
shuttle, said flow controller and said actuating means are of
plastics material.
17. A cartridge as claimed in claim 1, wherein said shuttle has an
O-ring carried on a rim of said shuttle and acting with said
intermediate barrel portion to provide the seal between said
shuttle and said intermediate barrel portion.
18. A cartridge as claimed in claim 1, wherein said shuttle has an
over-moulding of elastomeric material on a rim of said shuttle, the
over-moulding having a sealing protrusion acting with said
intermediate barrel portion to provide the seal between said
shuttle and said intermediate barrel portion and/or annular
portions at sealing faces adapted to co-operate with the aligned
barrel portions to close the respective inlets.
19. A cartridge as claimed in claim 1, including three outer seals
encircling the axis of said barrel for sealing to an outer body,
the seals comprising: a back seal for sealing the outlet of said
barrel from the inlet closer to the outlet; a front seal for
sealing the inlet further from the outlet from leaking to ambient;
and an oblique seal for sealing the inlet closer to the outlet from
the inlet further from the outlet, the oblique seal being spaced
further from the back seal to one side of the barrel and spaced
further from the front seal to the other side of the barrel.
20. A cartridge as claimed in claim 19, wherein the seals are
arranged to seal with a conical bore.
21. A cartridge as claimed in claim 19, wherein the seals are
O-rings carried in respective grooves on the outer surface of the
cartridge.
22. A cartridge as claimed in claim 19, wherein said barrel has an
outer collar integrally connected with said aligned barrel portion
having said outlet, said collar having: a first inlet between said
back seal and said oblique seal to one side of said barrel and a
second inlet between said front seal and said oblique seal to the
other side of said barrel, and said first and second collar inlets
communicating with said barrels inlets.
23. A cartridge as claimed in claim 22, wherein said collar inlets
communicate with said barrel inlets via plenum chambers extending
around said barrel.
24. A cartridge for a flow mixer comprising: a barrel having: an
outlet at one end of the barrel, two aligned barrel portions and a
intermediate barrel portion and the barrel portions providing: two
respective liquid inlets spaced along the barrel, one to one side
of the intermediate barrel portion and the other to the other side
thereof, and a shuttle mounted in the barrel in sealing
relationship with the intermediate barrel portion and axially
movable in the barrel, the shuttle and the barrel being adapted and
arranged to: close one of the inlets by co-operation with the
inlet's respective barrel portion and the intermediate barrel
portion when moved towards this barrel portion; close the other
inlet by co-operation with its respective barrel portion and the
intermediate portion when moved in the other direction and allow to
be open in a mid position, and the shuttle being apertured for flow
therethrough, a thermostatic capsule arranged within the barrel in
the flow of liquid through the inlets and adapted to control the
position of the shuttle for selection of flow from the two inlets,
a combined-flow control member ("flow controller") arranged
downstream of the thermostatic capsule at the outlet end of the
barrel for controlling the combined flow from the inlets and three
outer seals encircling the axis of the barrel for sealing to an
outer body, the seals comprising: a back seal for sealing the
outlet of the barrel from the inlet closer to the outlet; a front
seal for sealing the inlet further from the outlet from leaking to
ambient; and an oblique seal for sealing the inlet closer to the
outlet from the inlet further from the outlet, the oblique seal
being spaced further from the back seal to one side of the barrel
and spaced further from the front seal to the other side of the
barrel.
25. A cartridge as claimed in claim 24, wherein said seals are
arranged to seal with a conical bore.
26. A cartridge as claimed in claim 24, wherein said seals are
O-rings carried in respective grooves on said outer surface of said
cartridge.
27. A cartridge as claimed in claim 24, wherein said barrel has an
outer collar integrally connected with said aligned barrel portion
having said outlet, said collar having: a first inlet between said
back seal and said oblique seal to one side of said barrel and a
second inlet between said front seal and said oblique seal to the
other side of said barrel, and said first and second collar inlets
communicating with said barrels inlets.
28. A cartridge as claimed in claim 27, wherein said collar inlets
communicate with said barrel inlets via plenum chambers extending
around said barrel.
29. A cartridge as claimed in claim 24, including: means including
at least one finger passing through said shuttle for actuating said
flow controller to control said combined flow.
30. A mixer tap for mixing two liquid flows, the tap comprising: an
outer body, having a central cavity with an open front, a rear
outlet from the central cavity and two opposed inlets from the
sides of the body, the inlets in the body being at least
substantially coaxial and the cavity being adapted for sealing; and
a cartridge as claimed in claim 1, the cartridge sealing with the
body via the outer collar: firstly at the open front of the central
cavity, secondly obliquely in the cavity to direct flow from one
body inlet to one cartridge inlet and flow from the other body
inlet to the other cartridge inlet, thirdly at the rear of the body
to direct flow from the cartridge outlet to the body rear.
31. A mixer tap as darned in claim 30, wherein said outer body is
of forged brass.
32. A mixer tap as claimed in claim 30, wherein said cavity is
tapered with a larger diameter parallel land at said open front for
said first seal, a frusto-conical, intermediate portion for said
second, oblique seal and a smaller parallel land for said third
seal adjacent said rear outlet, said seals being O-rings carried on
said outer collar.
33. A shuttle for a flow mixer cartridge, said shuttle comprising a
rim with two annular end faces for sealing with respective aligned
barrel portions of said cartridge, said annular end faces being
provided with an over-moulding of elastomeric material for sealing
engagement with said respective aligned barrel portions.
34. A shuttle as claimed in claim 33, wherein said rim has a groove
for an O-ring arranged to seal to an intermediate barrel portion of
said cartridge.
35. A shuttle as claimed in claim 34, wherein said over-moulding
has a sealing protrusion arranged to seal to an intermediate barrel
portion of said cartridge.
Description
TECHNICAL FIELD
The present invention relates to a cartridge for a flow mixer and a
mixer for two liquid flows at different temperatures, particularly
though not exclusively for thermostatic mixing of water in a
shower.
BACKGROUND OF THE INVENTION
It is known to employ a thermostatic capsule to move a shuttle to
open or close small gaps on either side of the shuttle. It is
convenient for this shuttle to be circular with the gaps being
annular, but this gives rise to other problems.
The inlet to the annular gaps is conveniently radially inwards,
with mixed flow then passing axially to the thermostatic capsule.
This arrangement calls for flow regulation downstream of the
capsule and on the side of the capsule opposite from flow and
temperature controls. Conventionally, the flow control has been
carried out by means of a member spaced radially outwards of the
shuttle. This mitigates against a compact structure.
SUMMARY OF THE INVENTION
The object of the invention is to provide an arrangement wherein a
flow control member passes inwardly of the shuttle to provide a
more compact structure. A secondary object is to provide a more
compact inlet flow arrangement.
According to the invention there is provided a cartridge for a flow
mixer comprising: a barrel having: an outlet at one end of the
barrel, two aligned barrel portions and a intermediate barrel
portion and the barrel portions providing: two respective liquid
inlets spaced along the barrel, one to one side of the intermediate
barrel portion and the other to the other side thereof, and a
shuttle mounted in the barrel in sealing relationship with the
intermediate barrel portion and axially movable in the barrel, the
shuttle and the barrel being adapted and arranged to: close one of
the inlets by co-operation with the inlet's respective barrel
portion and the intermediate barrel portion when moved towards this
barrel portion; close the other inlet by co-operation with its
respective barrel portion and the intermediate portion when moved
in the other direction and allow both inlets to be open in a mid
position, and the shuttle being apertured for flow therethrough, a
thermostatic capsule arranged within the barrel in the flow of
liquid through the inlets and adapted to control the position of
the shuttle for selection of flow from the two inlets, a
combined-flow control member ("flow controller") arranged
downstream of the thermostatic capsule at the outlet end of the
barrel for controlling the combined flow from the inlets and means
including at least one finger passing through the shuttle for
actuating the flow controller to control the combined flow.
Whilst it can be envisaged that the flow controller can have
various forms, such as a movable obturator closing an open end of
the barrel forming the outlet or an apertured cylinder closing one
or more outlet apertures in the barrel at the outlet end with the
end being closed; in the preferred embodiment, the flow controller
is a sleeve mounted in the barrel and sealing in its closed
position against a closed end of the barrel, thereby closing an
outlet aperture in the wall of the barrel adjacent its end.
Preferably, the flow control sleeve seals against a seal captivated
between the sleeve and the end of the barrel.
Where the shuttle is contained completely within the barrel, the
latter can be envisaged to be of unitary construction with the
inlets being apertures in the aligned portions. However, as in the
preferred embodiment, the two aligned barrel portions are distinct
parts which are sealed together, with the intermediate barrel
portion being integrally connected to one of the two barrel
portions, with the shuttle acting between opposed ends of the two
portions.
The actuating means for the flow controller can be an integral part
of the flow controller, such as one or more fingers integrally
moulded with the flow controller and engaging an actuator at the
opposite side of the shuttle from the flow controller and the
thermostatic capsule, or it can be one or more fingers extending
integrally extending from the actuator and engaging the flow
controller. It can also be envisaged that the actuating means can
be separately formed and engaged with both the flow controller and
the actuator.
The actuator is conveniently a sleeve splined or otherwise
irrotationally held in the barrel and a rotary member carried by
the barrel, the sleeve and the rotary member being adapted to
convert rotation of the rotary member into translation of the
actuator and the flow controller. Whilst its conceivable that the
actuator could be sealed to the barrel and to the rotary member at
the rotary motion converter, a more practical arrangement is to
seal the barrel to the rotary member which will usually extend
inside the actuator.
A similar rotary to translational movement arrangement for
effecting temperature regulation with the thermostatic capsule is
preferably provided within the flow control actuator/rotary-member
assembly.
Preferably the cartridge is of moulded plastics components, with
the exception of the thermostatic capsule, associated springs,
seals and other fittings.
In one embodiment, the shuttle has an O-ring carried on a rim of
the shuttle and acting with the intermediate barrel portion to
provide the seal between the shuttle and the intermediate barrel
portion.
In another embodiment the shuttle has an over-moulding of
elastomeric material on a rim of the shuttle, the over-moulding
having a sealing protrusion acting with the intermediate barrel
portion to provide the seal between the shuttle and/or the
intermediate barrel portion and annular portions at sealing faces
adapted to co-operate with the aligned barrel portions to close the
respective inlets.
In respect of the secondary object, it is generally inconvenient to
provide stepped water ways for hot and cold water in the body of a
tap receiving a mixer cartridge. Nevertheless, since aesthetics can
require that externally the water ways should be co-axial, stepped
water ways are often provided. Where, as is usual, the body is of
brass, this mitigates against stampings in favour of castings
despite stampings being cheaper.
In accordance with an important preferred feature of the invention,
the cartridge includes three outer seals encircling the axis of the
barrel for sealing to an outer body, the seals comprising: a back
seal for sealing the outlet of the barrel from the inlet closer to
the outlet; a front seal for sealing the inlet further from the
outlet from leaking to ambient; and an oblique seal for sealing the
inlet closer to the outlet from the inlet further from the outlet,
the oblique seal being spaced further from the back seal to one
side of the barrel and spaced further from the front seal to the
other side of the barrel. The oblique seal allows opposed waterways
to the cartridge to be coaxial. Preferably, the seals are arranged
to seal with a conical bore. Conveniently the seals are O-rings
carried in respective grooves on the outer surface of the
cartridge.
In accordance with another important feature of the invention, the
barrel has an outer collar integrally connected with the aligned
barrel portion having the outlet, the collar having: a first inlet
between the back seal and the oblique seal to one side of the
barrel and a second inlet between the front seal and the oblique
seal to the other side of the barrel, and the first and second
collar inlets communicating with the barrels inlets.
Whilst it can be envisaged that the outer collar can be separate
and sealed to the barrel or one of its parts, in the preferred
embodiment, the outer collar is integral with one part of the
barrel. Preferably, the collar inlets communicate with the barrel
inlets via plenum chambers extending around the barrel.
According to another aspect of the invention, there is provided A
cartridge for a flow mixer comprising: a barrel having: an outlet
at one end of the barrel, two aligned barrel portions and a
intermediate barrel portion and the barrel portions providing: two
respective liquid inlets spaced along the barrel, one to one side
of the intermediate barrel portion and the other to the other side
thereof, and a shuttle mounted in the barrel in sealing
relationship with the intermediate barrel portion and axially
movable in the barrel, the shuttle and the barrel being adapted and
arranged to: close one of the inlets by co-operation with the
inlet's respective barrel portion and the intermediate barrel
portion when moved towards this barrel portion; close the other
inlet by co-operation with its respective barrel portion and the
intermediate portion when moved in the other direction and allow to
be open in a mid position, and the shuttle being apertured for flow
therethrough, a thermostatic capsule arranged within the barrel in
the flow of liquid through the inlets and adapted to control the
position of the shuttle for selection of flow from the two inlets,
a combined-flow control member ("flow controller") arranged
downstream of the thermostatic capsule at the outlet end of the
barrel for controlling the combined flow from the inlets and three
outer seals encircling the axis of the barrel for sealing to an
outer body, the seals comprising: a back seal for sealing the
outlet of the barrel from the inlet closer to the outlet; a front
seal for sealing the inlet further from the outlet from leaking to
ambient; and an oblique seal for sealing the inlet closer to the
outlet from the inlet further from the outlet, the oblique seal
being spaced further from the back seal to one side of the barrel
and spaced further from the front seal to the other side of the
barrel.
According to a third aspect of the invention there is provided a
mixer tap for mixing two liquid flows, the tap comprising: an outer
body, having a central cavity with an open front, a rear outlet
from the central cavity and two opposed inlets from the sides of
the body, the inlets in the body being coaxial and the cavity being
adapted for sealing; and a cartridge of the second aspect of the
invention, the cartridge sealing with the body via the outer
collar: firstly at the open front of the central cavity, secondly
obliquely in the cavity to direct flow from one body inlet to one
cartridge inlet and flow from the other body inlet to the other
cartridge inlet, thirdly at the rear of the body to direct flow
from the cartridge outlet to the body rear.
Preferably the outer body is of forged brass.
Preferably the cavity is tapered with an larger diameter parallel
land at the open front for the first seal, a frusto-conical,
intermediate portion for the second, oblique seal and a smaller
parallel land for the third seal adjacent the rear outlet, the
seals being O-rings carried on the outer collar.
Normally the rear body outlet will be upwardly directed with
respect to the tap orientation when a common plane of the central
cavity and the two body inlets is horizontal.
According to a fourth aspect of the invention there is provided a
shuttle for a flow mixer cartridge, the shuttle comprising a rim
with two annular end faces for sealing with respective aligned
barrel portions of the cartridge, the annular end faces being
provided with an over-moulding of elastomeric material for sealing
engagement with the respective aligned barrel portions.
Whilst the rim can have a groove for an O-ring arranged to seal to
an intermediate barrel portion of the cartridge; preferably the
over-moulding has a sealing protrusion arranged to seal to an
intermediate barrel portion of the cartridge.
BRIEF DESCRIPTION OF THE DRAWINGS
To help understanding of the invention, a specific embodiment
thereof will now be described by way of example and with reference
to the accompanying drawings, in which:
FIG. 1 is a perspective view of a mixer tap of the invention, with
control knobs shown broken away;
FIG. 2 is cross-sectional view through a body of the tap, showing
its flow mixing cartridge;
FIG. 3 is a similar view showing the cartridge in
cross-section;
FIG. 4 is a scrap cross-sectional view in the other plane of a
shuttle in the cartridge;
FIG. 5 is a cross-section view of the cartridge on a larger scale
than FIG. 3;
FIG. 6 is a scrap view of a modified shuttle with a shut-off
seal;
FIG. 7 is a scrap cross-sectional view of the outlet of the mixer
tap with an alternative flow controller, shown open in the left
half of the Figure and closed in the right half of the Figure;
FIG. 8 is similar view of an alternative unitary collar (with other
components except for the shuttle omitted);
FIG. 9 is a similar view of two alternative actuating finger
arrangements, in the respective left and right halves of the
Figure; and
FIG. 10 is a view similar to FIG. 8 of an alternative barrel and
shuttle configuration.
DETAILED DESCRIPTION
Referring to the drawings, the mixer tap for a shower there shown
has a body 1, with a cold water pipe connection 2, a hot water pipe
connection 3 and a mixed water outlet connection 4. A flow control
knob 5 and a water temperature control knob 6 are provided at the
front of the tap.
At the heart of the tap is a flow mixer cartridge 11, which is
sealed in a cavity 12 in the body via an outer collar 14. The
collar has three sealing grooves 15,16,17 carrying O-rings
115,116,117. The front groove 15 is a plain circular groove and its
O-ring mates with a circular-cylindrical land 215 at the front of
the body cavity 12. Equally the rear groove 17 is also a plain
circular groove of smaller diameter than the front groove 15 and
its O-ring mates with a circular-cylindrical land 217 at the back
of the body cavity 12. Between the lands, the cavity has a
frusto-conical wall 216. The groove 16 and its O-ring 116 have a
complementary, oblique shape.
To one side, the right hand side in FIGS. 2 & 3, between the
front groove 15 and the oblique groove 16, the collar has a cold
water port 22; whilst to the other side between the back groove 17
and the oblique groove 16, the collar has a hot water port 23.
These ports are in communication with the cold and hot water
connections 2,3 in the body, via inlet plena portions 122,123 of
the cavity between the body and the collar. The connections are
able to be axially aligned with each other, since the ports 22,23
are offset and isolated from each other by the oblique seal. Thus
with the body forged from brass, the inlet pipe connections can be
formed by straight forward machining operations.
The collar 14 is an injection moulding of plastics material and is
integrally moulded with an rear barrel portion 31, the collar being
generally frusto-conical to match the shape of the body cavity;
whilst the barrel portion is parallel with an end face 131. The
collar moulding has a closed end 32, closing both the collar and
the barrel. In an extension 33 of the barrel beyond the collar,
there is an outlet port 34. This opens to a rear outlet plenum
portion 134 of the cavity, from which latter in turn the outlet
connection 4 extends.
A front barrel moulding 41 is fitted to the rear-barrel collar
moulding 14/31, mating with it at a flange 35, adjoining the
sealing groove 15, and at an inner sealing land 36. A flange 42 of
the front barrel moulding abuts the flange 35 and the two are held
together by a threaded ring 7 in the body 1 at the mouth of the
cavity 12. An O-ring 43 is captive between the flanges and seals
them. The flange 42 extends in to support the front barrel proper
44, whose internal diameter is slightly larger that of the rear
barrel and which has a rear end face 144 opposite the front end
face 131 of the rear barrel. The rim flange 51 of a shuttle 52 is
positioned between the faces 131,144, with a small clearance. The
front barrel extends back as a sealing groove 45 past the end face
144 and is provided with an O-ring 145, which seals on a land 245
of the collar 14, the land forming an intermediate portion of the
barrel. The seal 45/145/245 divides the internal space of the
collar into inner, cold and hot, plena portions 222,223. These are
in communication with the respective small clearance cold and hot
gaps 322,323 between the barrel end face 144 and the shuttle and
the barrel end face 131 and the shuttle. The connection between the
front barrel 44 and the sealing groove 45 is apertured 46. Thus
water can flow from the cold and hot plena portions 222,223 via the
cold and hot gaps 322,323 into the barrels 44,31 in accordance with
position of the shuttle. In other words, the cold and hot gaps
322,323 provide hot and cold inlets into the combined barrel. This
water flow path into the combined barrel is illustrated in FIG. 5
by the inward pointing arrows 322 for cold water flow, and 323 for
hot water flow.
The shuttle itself is apertured 53, so that flow can pass it from
the front barrel 44 to the rear barrel 31 and onto the outlet port
34. The shuttle is fitted to a thermostatic capsule 61, which has
an expansive wax chamber 62, a support flange 63 and an actuating
push rod 64, which is pushed out of the capsule in response to the
wax chamber experiencing increased temperature. This action adjusts
the cold and hot gaps 322,323. Since it is possible for a sudden
increase in temperature, as in first use of a shower when hot water
first arrives, to extend the push rod by more than the aggregate of
the gaps, the connection between the shuttle and the capsule is via
a spring reactor 71. It and the shuttle have complementary
abutments 54,72, which are arranged to allow the capsule to move
back in the cartridge on such over temperature causing the shuttle
to bottom on the rear barrel end face 131. This movement apart of
the abutments is against the action of a spring 73 acting between
the abutment 54 and a clip 74 on a forwards extension 75 of the
reactor. The spring normally keeps the abutments 54,72 together,
whereby the movement of the support flange 63 of the capsule is
transmitted to the shuttle via a seat 76 for the support flange.
The spring reactor 71 also has a rearwards extension 77, which is
apertured 78 for water flow to the wax chamber 62, with a flange 79
for a main spring 80 against which the capsule normally acts for
adjustment of the position of the shuttle. The spring reacts
against a sealing washer 83 and the closed end 32 of the collar
moulding.
A flow controller 81 is provided within the rear barrel. It is in
the form of a sleeve carrying two O-rings 181 for sealing with the
rear barrel and having an end face 82 for abutment with the sealing
washer 83 carried inside the closed end 32 of the collar moulding.
The sleeve has integral fingers 84, which extend forwards through
certain of the apertures 53 in the shuttle. Rearwards movement of
the flow controller throttles and ultimately closes the tap by
isolating the inner, outlet plenum portion 234 of the cartridge, in
which the wax chamber 62 is positioned, from the outer, plenum
portion 134 of the cavity 14. More specifically, the sleeve end
face 82 abuts the sealing washer 83 and isolates the outlet port 34
from the inlet ports 22,23.
The arrangements for longitudinal actuation of the flow control
sleeve 81 and the capsule/shuttle 61/52 will now be described.
Essentially, they comprise splined members driven longitudinally by
screw thread co-operation with rotary members restrained from
longitudinal movement.
The front barrel moulding 41 has internal splines 47, open towards
the rear and terminating short of a smaller diameter plain bore 48
and a turned-in, front rim 49 of the moulding. An actuating sleeve
85 has complementary outer splines 86 for sliding movement in the
barrel without rotation. It has a skirt 87 with apertures 88 in
which hooks 89 at the end of the fingers 84 engage. The sleeve 85
has an internal screw thread 90 and internal splines 91 proud of
the thread at the inner end of the sleeve.
An actuation threaded member 92 is provided at the front of the
barrel moulding, being longitudinally restrained in it by abutment
of a step 93 against the inside of the rim 49 and of a circlip 95
against the outside of the rim, the circlip being engaged in a
groove 96 in the actuation member 92. A pair of O-rings 192 engage
in grooves in the member and seal it to the barrel at the bore 48.
The member has an external screw thread 97 at its inner end,
engaged in the thread 90 of the sleeve 85, and a broached outer
head 98 engaged in the flow control knob 5. Thus the threaded
member is rotatable but axially restrained; whilst the sleeve is
rotationally restrained but axially movable. On turning of the knob
5, the actuating sleeve 85 is moved axially and with it the sleeve
81, moving its end face 82 towards or away from the sealing washer
83. Thus the overall flow through the tap is controlled.
Housed within the flow control actuation threaded member 92 is a
spacer sleeve 99, with a step and circlip axial restraint similar
to that of the threaded member. It has external splines 100 engaged
with the splines 91 of the actuating sleeve 85. Thus sleeve is
restrained against axial and longitudinal movement. It is also
sealed by an O-ring 199 to the member 92. Mounted within the sleeve
99 in exactly like manner to the members 85, 92 are a thermostat
actuating member 101 and a thermostat actuation threaded member 102
with a broached head 103 to which the water temperature control
knob 6 is fitted. The actuating member 101 has an indented inner
end 104 against which the push rod 64 of the thermostatic capsule
abuts. Rotation of the temperature control knob 6 moves the shuttle
52 under the action of the reaction spring 73 or the main spring 80
to close the respective gap 322,323 to raise or lower the outlet
water temperature as the temperature changes. After initial shuttle
movement, the capsule will change length to adjust the shuttle back
in the opposite direction and thus control the temperature to the
newly selected one.
It will be appreciated from the fact that the cartridge is shown in
FIG. 5 reversed right for left in comparison with FIG. 3, that it
can be fitted in either orientation to suit left or right entry of
cold--and hot--water into the body of the tap. This is a distinct
advantage in that it is not unknown for plumbers to reverse the
plumbing accidentally.
Referring now to FIG. 6, a scrap view of a modified shuttle is
there shown. In place of an O-ring 55 carried on the rim of the
shuttle and acting inside the grooved portion 45 of the front
barrel, to separate the cold and hot plena 222,223, the shuttle 452
has an over-moulding 455 of elastomeric material. This has a
sealing protrusion 4551 acting in the manner of the O-ring and
annular portions 4552,4553 at the cold and hot gaps 322,323. This
has the advantage that in the event of failure of either hot or
cold water supply, the thermostatic capsule drives the shuttle in
the direction to fully open the failed supply and fully close the
remaining supply. This has the effect of turning off the tap.
Provision of the moulding at the gaps enables the shuttle to fully
seal the gap corresponding to the remaining supply.
The invention is not intended to be restricted to the details of
the above described embodiment. For instance, it can be envisaged
that the oblique seal could be configured as a front to back seal
in the vertical plane. However, the O-ring would have to be
replaced in that instance.
The flow controller can be provided as an apertured cylinder 581
co-operating with the rear barrel portion 531 as shown in FIG. 7.
Barrel apertures 534 align with apertures 5811 in the cylinder when
the mixer tap is open and are out of alignment to close the tap.
When the tap is closed two O-rings on the cylinder are positioned
above and below the barrel apertures, sealing them.
As shown in FIG. 8, the rear barrel portion 631 can be formed as
one, or integrally welded together, not only with the collar 614,
but also with the land 645 to dispense with the necessity of seal
145.
As shown in the left hand side of FIG. 9, the actuating fingers 784
can be integral with the actuating sleeve 785 and clipped to the
flow control member 781. Alternatively as shown in right hand side
of the Figure fingers 884 can be clipped to both the actuating
sleeve 885 and the flow control member 881, with the fingers being
spaced circumferentially by means of an integral ring 8841.
Another alternative arrangement is shown in FIG. 10, in which the
two aligned barrel portions 931,941 and the intermediate portion
945 of the barrel are all integral parts of unitary construction.
The barrel has cold and hot inlets 922,923 in the form of apertures
in the walls of the barrel between the front portion and the
intermediate portion and between the intermediate portion and the
rear portion. The shuttle 952 is contained within the barrel has an
O-ring 955 sealing it to the intermediate portion. It moves to seal
either the sets of ports as required.
* * * * *